Alaska Extended Forecast Discussion NWS Weather Prediction Center College Park MD 642 PM EDT Thu Aug 13 2020 Valid 12Z Mon Aug 17 2020 - 12Z Fri Aug 21 2020 ...Guidance Evaluation and Preferences... Overall, model/ensemble guidance showed near to above average consensus through the extended forecast period. A blend of the 12Z ECMWF/CMC was used heavily as a forecast starting point initially on day 4 (Mon). A gradual trend toward increased weight placed on ensemble means (ECENS/NAEFS) was shown through time, with majority ensembles in the blend during days 7-8 (Thu-Fri). Overall, guidance is consistent in showing a fairly amplified pattern continuing, with an upper trough persistent across the Gulf of Alaska, and ridging attempting to build across the Bering Sea next week. ...Weather Highlights/Threats... A low pressure system across the Gulf of Alaska will weaken by early next week, but could bring heavy rain to portions of the Alaska Panhandle into Monday. A second low pressure system is forecast to cross the Bering Sea Mon, with a triple point low near the Alaska Peninsula becoming dominant by Tue, and the system expected to once again move east across the Gulf of Alaska from there through the middle/end of next week, keeping precipitation a distinct possibility across southern mainland Alaska as well as the Panhandle. Farther north, a weakening frontal boundary expected to settle into the Interior should bring scattered showers by next Tue-Wed. By later next week, as upper ridging potentially builds across the Bering Sea and western mainland Alaska, drier conditions should prevail across much of mainland, with only the Panhandle/Southeast Alaska remaining wet. In general, this pattern should favor temperatures several degrees above average across much of the state. The North Slope will see decreasing temperatures in the wake of the cold front next week, with high temperatures expected to drop to a few degrees below average. Ryan Additional 3-7 Day Hazard information can be found on the WPC medium range hazards chart at: https://www.wpc.ncep.noaa.gov/threats/threats.php Hazards: - Heavy rain across portions of the Alaska Panhandle, Sun-Mon, Aug 16-Aug 17. WPC medium range Alaskan products including 500mb, surface fronts/pressures progs and sensible weather grids can also be found at: https://www.wpc.ncep.noaa.gov/alaska/ak_5dayfcst500_wbg.gif https://www.wpc.ncep.noaa.gov/alaska/akmedr.shtml https://www.wpc.ncep.noaa.gov/alaska/ak_5km_gridsbody.html